Lipitor is a medication that is used to lower cholesterol levels in the body. It is known to have some potential side effects, including liver damage. Therefore, it is recommended to perform liver function tests (LFTs) before starting Lipitor and periodically thereafter to monitor liver function [2]. The frequency of these tests may vary depending on the patient's age, medical history, and other factors. In general, LFTs should be done before starting the medication, then repeated after 12 weeks, and then annually thereafter [3]. However, in some cases, more frequent testing may be necessary, especially if the patient has a history of liver disease or experiences symptoms such as abdominal pain, jaundice, or fatigue [2]. It is important to note that while Lipitor can cause liver damage, this is a rare occurrence, and most patients can take the medication safely [1]. If you have any concerns about the frequency of your liver function tests while taking Lipitor, you should speak with your healthcare provider.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/books/NBK548236/
[3] https://www.nhsinform.scot/tests-and-treatments/medicines-and-medical-aids/types-of-medicine/statins